1. Field of the Invention
This invention relates generally to contact lens storage cases, and more particularly to contact lens storage cases having domes for holding contact lenses while they are immersed in soaking solution contained in the storage cases.
2. Description of the Prior Art
Storage cases having hard plastic domes for holding contact lenses while they are suspended in soaking solutions are well known. Representative patents disclosing such domes are found in U.S. Pat. Nos. 3,770,113; 3,997,049, and 3,990,579. As seen in FIG. 3 of U.S. Pat. No. 3,997,049 and FIG. 1 of U.S. Pat. No. 3.770,113 hard plastic domes of this type are very often attached to stems which are, in turn, attached to the inside of the cap which closes the storage case. As can be seen in the drawings accompanying these patents, the domes can be enclosed by hinged covers which encompass the contact lenses and the domes upon which they rest. The covers are made of a hard plastic and usually have apertures for allowing the soaking solution to contact the lens. These covers are also provided with a locking means such as prongs which engage with a biased catch near the base of the dome by a pressure fit and thereby hold the cover closed over the dome. Finger pressure is used to overcome the bias of the receiver to open the cover. Usually the hinge at the back of the cover and the prong at the front of the cover engage with their respective cooperating parts at or near the base of the dome. Therefore, the edges of the contact lenses, particularly so called soft contact lenses, are sometimes crimped or pinched by either the hard plastic prongs or by the hinges when the cover is closed down upon a lens which has slipped from the crown of the dome. When the lens does slip from the crown of the dome it is not uncommon for it to come to rest beyond the base of the dome. When this happens it can be damaged by the descending prong or the fulcrum formed at the hinge. Furthermore the base of these domes often rest in a tray-like base. There is very little room between the sides of the tray and the dome. When, due to the suction forces created between the lubricated concave side of the lens and the dome, a lens gets stuck on the dome there is usually not enough room to get a finger tip between the sides of the tray and the dome to lift the rim of the lens and break the suction forces. When confronted with this problem most users usually retrieve the lens by pinching it between their thumb and index finger. This action often proves to be injurious to soft contact lenses. Furthermore the holders with their trays, domes, hinged covers, suspension devices and other parts are made individually and then precisely assembled for correct mechanical operation. These features tend to lead to relatively costly contact lens storage cases which must sometimes be replaced when individual parts are lost. Applicant has found that potential damage to contact lenses, particularly soft contact lenses, caused by both the mechanical operation of the holder in which the lens is stored, and by the act of overcoming the suction forces which may hold the lens to the dome, can be minimized by use of a single unit, mushroom shaped holder having indentations in the side of the dome and a cover comprised of a strap which engages with a receiver located under the dome.